Workplace productivity and personal relationships the world over could soon be taking a hit: The man behind the world-wide mobile gaming sensation “Flappy Bird” has unleashed his newest effort.

Dong Nguyen, the shy Vietnamese developer whose famously challenging title winged its way to the top of the App Store and Google Play earlier this year, on Thursday released his newest work, called “Swing Copters.”

The iOS and Android smartphone game is free, with an optional $0.99 in-app purchase to remove advertising. It is now available in some countries’ App Stores and on Google Play. Dong has written on Twitter that it will soon be available in more countries.

Like its predecessor, “Swing Copters” appears potentially habit-forming — and is extraordinarily difficult.

Players must steer a small creature with large eyes and a propeller hat from the ground up into the sky, through what look like large swinging gavels suspended from girders. If the creature is hit, it plummets to the ground, then blinks its eyes incredulously.

“Dong Nyguen, it looks like you have done it again,” one commentor on the TouchArcade article wrote. Other readers, however, criticized the game, saying it appeared to be merely a vertical rendition of “Flappy Bird.”